The present technology relates to a storage controlling apparatus. More particularly, the present technology relates to a storage controlling apparatus, a storage apparatus and an information processing system for a nonvolatile memory and a processing method for the storage controlling apparatus, storage apparatus and information processing system as well as a program for causing a computer to execute the processing method.
In an information processing system, a DRAM (Dynamic Random Access Memory) or a like device is used as a work memory. The DRAM normally is a volatile memory, and if supply of power thereto stops, then the stored contents thereof are lost. On the hand, in recent years, nonvolatile memories (NVM) have been used. Such nonvolatile memories are roughly divided into flash memories ready for data accessing in a unit of a large size and nonvolatile random access memories (NVRAM: Non-Volatile RAM) which allow high speed random access thereto in a small unit. A representative one of the flash memories is a NAND type flash memory. Meanwhile, the nonvolatile random access memories include a ReRAM (Resistance RAM), a PCRAM (Phase-Change RAM), an MRAM (Magnetoresistive RAM) and so forth.
Among the nonvolatile random access memories, the ReRAM is a resistance change memory which uses a variable resistive element. The variable resistive element of the ReRAM can record information of one bit in two states including a high resistive state (HRS) and a low resistive state (LRS). To the ReRAM, it is necessary to apply drive voltages of different potentials depending upon whether the variable resistive element is to be changed into the high resistive state or the variable resistive element is to be changed into the low resistive state. This is described, for example, in Japanese Patent Laid-Open No. 2010-140526.